Physical separation of cells by filtration

Abstract

Method for the selective separation of cell mixtures by filtration. A filter with well defined pores that is stable under pressure is used, and the driving force for filtration is preferably centrifugation. Cells smaller than the nominal pore size pass through the filter, while cells larger than the pores in the filter are retained.

1 . (Amended) A method for separating a mixture of epithelial cells and sperm cells based on size by filtration, comprising contacting a filter that has defined pore sizes and whose pores are stable under pressure, with said mixture and forcing said mixture against said filter without substantially altering said pore size, said filter having a mean pore size effective for retaining said epithelial cells while allowing said sperm cells to pass through said pores when a driving force is applied.  
     
     
         2 . (unchanged) The method of  claim 1  wherein said mixture is forced against said filter using centrifugation.  
     
     
         3 . (unchanged) The method of  claim 1  wherein said mixture is forced against said filter using pressure.  
     
     
         4 . (unchanged) The method of  claim 1  wherein the filter is a track-etched filter.  
     
     
         5 . (unchanged) The method of  claim 4 , wherein said track-etched filter is polycarbonate.  
     
     
         6 . (Amended) The method of  claim 1 , wherein at least 50% of said pores differ in size by no more than 40% from said mean pore size.  
     
     
         7 . (Amended) The method of  claim 1 , wherein said filter has a plurality of pores which provide a direct flow path for said cells.  
     
     
         8 . (cancelled)  
     
     
         9 . (Amended) The method of  claim 1 , wherein said mean pore size of said filter is about 5 microns.  
     
     
         10 . (Amended) The method of  claim 1 , wherein said driving force is centrifugation at about 3000 g.  
     
     
         11 . (cancelled)  
     
     
         12 . (cancelled)  
     
     
         13 . (unchanged) The method of  claim 1 , wherein said method is carried out a plurality of times in parallel.  
     
     
         14 . (Newly added) A method for separating a mixture of lymphocytes and non-lymphoid cells based on size by filtration, comprising contacting a filter that has defined pore sizes and whose pores are stable under pressure, with said mixture and forcing said mixture against said filter without substantially altering said pore size, said filter having a mean pore size effective for retaining said lymphocytes while allowing said non-lymphocytes to pass through said pores when a driving force is applied.